Wat het doet
The Schistoscope provides point of care access to Schistosomiasis diagnostics by simplification and automation of diagnosis. It captures the urine sample in one picture, created by a new way of filtering, and an algorithm detects the level of infection.
Schistosomiasis is a waterborne neglected tropical disease with a high rate of morbidity and mortality in African countries. With 240 million people affected, it causes trouble in the mental development of children, fatal organ failure or bladder cancer. Due to lack of proper diagnostic methods, it is difficult to identify the endemic areas and treat infected populations. The WHO golden standard, laboratory microscopy, is expensive, time-consuming and requires special expertise. The Schistoscope will enable more affordable and accessible diagnosis in order to take vital actions, while being produced, used and maintained locally.
Hoe het werkt
The Schistoscope uses a smartphone in combination with a reversed lens to identify Schistosomiasis eggs of 100 μm in urine samples. The 3D printed internal framework developed hangs in the embodiment to enhance stability. This structure guides the movement of the sample precisely under the lens, while limiting the stacking of tolerances to 0.23 mm. The sample preparation unit is designed to be easy-to-use and leakproof. It results in a sample with a diameter of 3.5 mm, which can be captured by one field of view (picture). A one-axis movement system, controlled manually with a knob, decreases wear and dampens by using leaf springs, giving the user smooth control while creating continuous small steps of movement for focusing. The Schistoscope has a limited amount of electronic components, uses minimal amount of power, and can be easily repaired; increasing the durability of the device. The pictures taken can automatically be sent for digitized data collection.
We started with a basic prototype that demonstrates the optical system with a reversed lens and a smartphone. To keep the design of Schistoscope as simple as possible, we optimized our system to a smartphone available in the market. Using a camera module of the phone yielded unexpected challenges such as a small field of view and the instability of the housing. To create a high-quality image sufficient for diagnosis, we thoroughly analyzed the concept and divided into three subsystems: optics, focus mechanism, and sample preparation unit. A list of requirements (LoR) was defined after evaluating the systems on their feasibility, desirability, and viability. This LoR has been an iterative process, consulting many experts within precision systems, optics, 3D printing, and the medical field, eventually used to validate our final design. Overall, the three sub-systems were developed in parallel. We went through many iterations of rapid prototyping and often came together to validate decisions on their integration. We explored diverse prototyping techniques from cardboard, FDM, polyjet, SLA printing, laser cutting and CNC milling. Finally, we were able to validate our design and its system by capturing images from real urine samples containing schistosoma eggs in a lab setting.
Hoe onderscheidend is het?
The Schistoscope is a simple yet smart onsite diagnostic device that can be produced and maintained locally in Africa. Its ease of use and smart algorithm allow local healthcare workers with low education to perform diagnosis test. Using the Schistoscope, up to 50 tests can be performed in a day, significantly improving the control and elimination of Schistosomiasis in the remote areas by bringing access to affordable diagnosis. Current microscopy requires high-precision tasks to make urine samples and 3 axes of focus. Our device has one field of view and one movement axis making it much easier to control. The ergonomic design of the sample preparation unit makes it easy to filter urine and precisely position. The optics system shows the spine of the parasitic egg which allows species identification. The 3D printed parts can be replaced locally. Critical parts, e.g. focus mechanism thread & sample holder, are made of stainless steel for durability and cleaning.
In the coming months, the Schistoscope will be tested with the end-users in Africa. Based on the feedback, we will further improve our design. Furthermore, the components of the Schistoscope need to be evaluated and tested once more with the correct materialization. Besides that, the algorithm needs to be optimized further by capturing more images for the machine learning. Lastly, the data collection part of the system should be developed for mapping, control and elimination purposes.
No awards, but thank you to our coach Gerard Nijenhuis, client Diagnostics for All, all the experts who supported us, and TU Delft.